Sheet correcting device and printer

Abstract

A sheet correcting device includes a plurality of curved surface members including curved surfaces, respectively, to deform a sheet along the curved surfaces, the plurality of curved surface members disposed along a conveyance direction of the sheet, a plurality of pressing members disposed facing the curved surfaces of the plurality of curved surface members, respectively, to press the sheet against the curved surfaces of the plurality of curved surface members, respectively, a sheet tensioner to apply tension to the sheet, and a heater to heat the sheet that is bent by the curved surfaces of the plurality of curved surface members.

What is claimed is: 
     
       1. A sheet correcting device, comprising:
 a plurality of curved surface members including curved surfaces, respectively, to deform a sheet along the curved surfaces, the plurality of curved surface members disposed along a conveyance direction of the sheet; 
 a belt pair, including a first belt and a second belt to sandwich the sheet between the first belt and the second belt to convey the sheet in the conveyance direction; 
 a plurality of pressing member groups disposed facing the curved surfaces of the plurality of curved surface members via the belt pair, respectively, to press the belt pair against the curved surfaces of the plurality of curved surface members, respectively; and 
 a heater to heat the sheet that is deformed by the curved surfaces of the plurality of curved surface members; and 
 each of the plurality of pressing member groups including: 
 a first pressing member to press the belt pair against one of the curved surfaces; and 
 a second pressing member separate from the first pressing member and disposed adjacent to and upstream from the first pressing member of a corresponding pressing member group in the conveyance direction to press the belt pair against another of the curved surfaces, 
 wherein the first belt and the second belt are disposed to sandwich the sheet from the second pressing member of a first pressing member group to a first pressing member of the first pressing member group, 
 wherein the first belt and the second belt are disposed to sandwich the sheet from the second pressing member of a second pressing member group to a first pressing member of the second pressing member group, 
 wherein the first pressing member of the first pressing member group and the second pressing member of the second pressing member group press the belt pair against a same one of the plurality of the curved surfaces. 
 
     
     
       2. The sheet correcting device according to  claim 1 , wherein the plurality of curved surface members comprises a first curved surface member that bends the sheet convexly upward and a second curved surface member that bends the sheet convexly downward, and
 the first curved surface member and the second curved surface member are alternately disposed along the conveyance direction. 
 
     
     
       3. The sheet correcting device according to  claim 1 , wherein the plurality of curved surface members comprises a plurality of first curved surface members successively disposed to bend the sheet convexly upward and a plurality of second curved surface members successively disposed to bend the sheet convexly downward, and
 the plurality of first curved surface members is disposed next to the plurality of second curved surface members. 
 
     
     
       4. The sheet correcting device according to  claim 1 , wherein one of the plurality of curved surface members and another of the plurality of curved surface members disposed adjacent to and downstream from the one of the plurality of curved surface members in the conveyance direction are arranged at an interval at which the sheet is held straight between the first pressing member facing the another of the plurality of curved surface members and the second pressing member disposed upstream of the first pressing member in the conveyance direction and facing the one of the plurality of curved surface members. 
     
     
       5. The sheet correcting device of  claim 1 , wherein the first belt is an upper belt and the second belt is a lower belt. 
     
     
       6. The sheet correcting device according to  claim 5 , further comprising:
 a belt tensioner that applies a tensile force to the upper belt and the lower belt, respectively, in a direction in which each of belt surfaces of the upper belt and the lower belt of the belt pair that holds the sheet is pulled toward both upstream and downstream of the sheet in the conveyance direction. 
 
     
     
       7. The sheet correcting device according to  claim 1 , further comprising:
 a first urging member that urges the first pressing member to press the sheet against the curved surfaces; and 
 a second urging member that urges the second pressing member to press the sheet against the curved surfaces, 
 wherein the first urging member, the second urging member, the first pressing member, and the second pressing member form a sheet tensioner, and 
 an urging force of the second urging member is larger than an urging force of the first urging member. 
 
     
     
       8. The sheet correcting device according to  claim 1 , wherein each of the plurality of curved surface members is a roller. 
     
     
       9. The sheet correcting device according to  claim 1 , wherein each of the plurality of curved surface members includes a plurality of contact members disposed along the conveyance direction, and
 a leading end of one of the plurality of contact members disposed at a center in the conveyance direction protrudes beyond leading ends of the plurality of contact members disposed at both ends in the conveyance direction. 
 
     
     
       10. The sheet correcting device according to  claim 1 , wherein at least one of the first pressing member and the second pressing member is movable toward and away from the curved surface of a corresponding one of the plurality of curved surface members. 
     
     
       11. The sheet correcting device according to  claim 1 , wherein at least one of the first pressing member and the second pressing member is a roller. 
     
     
       12. The sheet correcting device according to  claim 1 , wherein the sheet correcting device corrects the sheet after a printing process and a drying process are performed on the sheet. 
     
     
       13. The sheet correcting device according to  claim 1 , wherein:
 the plurality of pressing member groups presses the sheet against the plurality of curved surfaces for a plurality of times via the first belt and the second belt while conveying the sheet. 
 
     
     
       14. A printer comprising:
 a liquid application device to apply liquid to a sheet; and 
 the sheet correcting device according to  claim 1 , 
 wherein the sheet correcting device is disposed downstream of the liquid applying device in the conveyance direction. 
 
     
     
       15. The printer according to  claim 14 , further comprising a drying apparatus to dry the sheet, disposed between the liquid application device and the sheet correcting device. 
     
     
       16. The printer according to  claim 14 , wherein the liquid application device is configured to discharge ink onto the sheet to form an image on the sheet. 
     
     
       17. A sheet correcting device, comprising:
 a plurality of curved surface members including curved surfaces, respectively, to deform a sheet along the curved surfaces, the plurality of curved surface members disposed along a conveyance direction of the sheet; 
 a belt pair, including a first belt and a second belt to sandwich the sheet between the first belt and the second belt to convey the sheet in the conveyance direction; 
 a plurality of pressing members disposed facing the curved surfaces of the plurality of curved surface members via the belt pair, respectively, to press the belt pair against the curved surfaces of the plurality of curved surface members, respectively; and 
 a heater to heat the sheet that is deformed by the curved surfaces of the plurality of curved surface members; and 
 each of the plurality of pressing members including: 
 a first pressing member to press the belt pair against one of the curved surfaces; and 
 a second pressing member separate from the first pressing member and disposed adjacent to and downstream of the first pressing member in the conveyance direction to press the belt pair against another of the curved surfaces, 
 wherein: 
 the plurality of pressing members presses the sheet against the plurality of curved surfaces for a plurality of times via the first belt and the second belt while conveying the sheet, 
 the plurality of curved surface members includes a first curved surface contacting the first belt, and a second curved contacting the second belt, 
 the first curved surface and the second curved surface are disposed opposite to each other via the belt pair, 
 the plurality of pressing members includes a first set of the first pressing member and the second pressing member configured to press the first curved surface via the belt pair, and a second set of the first pressing member and the second pressing member configured to press the second curved surface via the belt pair, and 
 the first set and the second set are disposed opposite to each other via the belt pair.